1. Field of the Invention
The present invention relates generally to power over Ethernet (PoE) and, more particularly, to a triggered restart mechanism for failure recovery in PoE.
2. Introduction
In a PoE application such as that described in the IEEE 802.3af and 802.3at specifications, a power sourcing equipment (PSE) can deliver power to a powered device (PD) over Ethernet cabling. Various types of PDs exist, including voice over IP (VoIP) phones, wireless LAN access points, Bluetooth access points, network cameras, computing devices, etc.
In accordance with IEEE 802.3af, a PSE can deliver up to 15.4 W of power to a single PD over two wire pairs. In accordance with IEEE 802.at, on the other hand, a PSE may be able to deliver up to 30 W of power to a single PD over two wire pairs. Other proprietary solutions can potentially deliver higher or different levels of power to a PD. A PSE may also be configured to deliver power to a PD using four wire pairs.
In an enterprise environment, network managers may have hundreds or even thousands of PDs to manage across a wide distribution area. This management task can be costly in practice. Consider, for example, a simple task such as power cycling. In this process, IT staff personnel would typically be sent out to locate a particular device and to unplug and re-plug a power cord to force a reboot of the device. This menial task is costly both in time and in resource. What is needed therefore is a triggered restart mechanism for failure recovery in PoE.